Mass spectrometers are used to determine the chemical composition of substances and structures of molecules. Mass spectrometers may comprise an ion source to produce ions—e.g., to ionized neutral molecules—as well as a mass analyzer and ion detector. The mass analyzer may be a time-of-flight (TOF) mass analyzer, for example. TOF mass spectrometers may be used to record the mass spectra of compounds or mixtures of compounds by measuring the times for molecular and/or fragment ions of those compounds to travel certain distances. Reflectrons (also known as ion minors) may be implemented in time-of-flight mass spectrometers to reverses the direction of travel of the ions entering the reflectron and to increase mass resolving power and sensitivity. Ions transmitted toward the reflectrons are deflected by the reflectron and received by an ion detector. The ion times of flight may be measured by the ion detector.